Multiple circuit breaker



y 1963 R. E. LOCHER 3,089,933

MULTIPLE CIRCUIT BREAKER Filed April 25, 1960 FIG. 1. 33

INVEA/TUR Ross 5 L 0 CHER B Y H/S A 7'7'0RA/EY? HARE/S, K/ECH, RUSSELL & KERN United States Patent Ofi ice 3,689,933 Patented May 14, 1963 3,089,933 MULTIPLE CIRQUIT BREAKER Ross E. Locher, San Marino, Califi, assignor to Zinsco Electrical Products, Los Angeies, Califi, a corporation of California Filed Apr. 25, 1960, Ser. No. 24,491 6 Claims. (or. 200-116) This invention relates to circuit breaker switches and, in particular, to improvements therein permitting a plurality of switches to be operated in multiple. In general, a circuit breaker switch is manually or externally actuable for movement between an open circuit or 01f condition and a closed circuit or on condition and is also automatically movable to another open circuit or tripped con dition when certain undesired conditions exist, the undesired condition usually being excessive current through the switch. After a circuit breaker switch has been tripped or switched to the tripped condition, it is necessary to manually or externally reset the switch to the off condition before it can again be moved to the on condition.

Two or more such switches may be used in an electrical circuit where it is desirable that all of the switching circuits be .open when any one of the switches has been tripped and that all of the switching circuits remain open as long as the undesired condition exists. Various mechanisms have been utilized in the past to provide this desired mode of operation, including those shown in the United States patents to Thomas, No. 2,779,831 and Locher, No. 2,878,332. It is an object of the invention to provide a new and improved mechanism for interconnecting circuit breaker switches to cause the interconnected switches to trip when any one of the switches is tripped. A further object is to provide such a mechanism which is extremely simple and reliable and one which provides a relatively high operating force. Another :object is to provide such a mechanism which may be readily incorporated into existing switch designs and one in which the additional parts are easily slid into and removed from the switch cases.

It is an object of the invent-ion to provide a circuit breaker switch having (a manually actuated cit-on switch mechanism and an automatic circuit breaking mechanism mounted in a case, with the automatic circuit breaking mechanism including a latch movable between a neutral position and a circuit interrupted position and a trigger arm released by the latch when in the circuit interrupted position to automatically interrupt the electrical circuit, and including a latch release member engageable with the latch to hold the latch in the neutral position, a thermal trip member engageable with the latch release member to move the latch release member out of engagement with the latch, means for mounting a plurality of the switches side-byside, and a cross link movably mounted in the side-by-side switches for engagement by a latch when in the circuit interrupted position to move the cross link into engagement with the latch release member of each of the switches to move the latch release members out of engagement with the corresponding latches and release the trigger arms of each switch. A further object is to provide such a structure wherein the latch release member is a leaf spring slid-ably positioned in the case and biased into engagement with the latch. A further object is to provide such a structure wherein the cross link for a pair of switches is a U-shaped plate pivotally mounted in the switches along the bight and having each arm extending to engage the latch release member of one of the switches.

The invention also comprises novel details of construc tion and novel combinations and arrangements of parts, which will more fully appear in the course of the following description. While the invention may be used with various types of circuit breaker switches, including those referred to above and that shown in the United States patent to Speck, No. 2,502,537, it is illustrated and described herein as applied to the circuit breaker shown in my copending application entitled Electrical Switch, Serial No. 841,497, filed September 22, 1959, and assigned to the same assignee as the present application.

In the drawing:

FIG. 1 is a top view of a pair of switches incorporating the invention;

FIG. 2 is a sectional view taken along the line 22 of FIG. 1;

FIG. 3 is a partial sectional view taken along the line 3-3 of FIG. 2;

FIG. 4 is a partial sectional view taken along the line 44 of FIG. 2;

FIG. 5 is a partial sectional view taken along the line 55 of FIG. 2;

FIG. 6 is a view similar to that of FIG. 2 showing the switch in the tripped position; and

FIG. 7 is an isometric view of the latch release member and associated parts.

Each switch mechanism is mounted in a case consisting of a body 15 and a cover plate 16. A fixed contact 17 is mounted on a conductor 18 having a U-shaped bus clip 19 at the other end. Housings 20, 21 are formed in the body 15 tor receiving the bus clip 19, with the housing being symmetrically positioned with respect to support boss 22 for the fixed contacts. The conductor 18 may be positioned in the body with the fixed contact on the boss 22 and with the bus clip in either of the housings 20, 21. Two or more switches may be joined together by suitable means such as rivets 23, to form a switch unit 24, as shown in FIG. 1.

The switch mechanism includes a moving contact 29 carried on a contact arm 30, a pivot arm 31, a switch actuator 32, a finger member 33, a trigger arm 34, a latch lever 35, a latch release member 26, a cross link 27, and a thermal trip member '36. A flexible conductor 37 is connected between the contact arm 30 and the thermal trip member 36, with the trip member being spot-welded to a conductor 38 fixed in the body by screws 39. A terminal member 40' is fixed to the conductor '38 for receiving an external wire which is fixed in the terminal by screw 41.

A toggle or overcenter spring 42 is connected between the contact arm 30 and the trigger arm 34, with the trigger arm serving as a fixed reference for the toggle spring during normal operation of the switch, as shown in FIG. 2. However, when the trigger arm 34 is released by the latch lever 35 under overload conditions, the trigger arm is rotated clockwise by the spring 42, moving the switch to the tripped, open circuit position, as shown in FIG. 6. The circuit breaker is reset by moving the finger member 33 to the extreme clockwise position, with an end portion 46 of the finger member engaging the trigger arm 34.

In the preferred form shown herein, the latch release member 26 is a leaf spring having an S-bend portion 50 atone end and a notched section 51 at the other end. The S-bend portion 50 is positioned over bosses 52, 53 formed in the case 15, permitting the spring to be slid into position in the switch mechanism. A tongue 54 of the latch lever 35 is positioned in the notch 51 when the circuit breaking mechanism is in the neutral position, as shown in FIGS. 2 and 7. This engagement of the tongue of the latch lever with the notch of the latch release member maintains the switch in the neutral condition so that it may be used as a switch and switched from off to on and return as desired.

The thermal trip member 36, which is ordinarily a bimetal strip, has an upstanding portion at its free end with aoaaass an overhanging shoulder 56, which is positioned for engaging the tip of the latch release member 26. When the current through the switch exceeds a predetermined value for a predetermined time, the thermal member rotates in a counterclockwise direction to engage the latch release member 26 and move the latch release member downward out of engagement with the latch lever 35. When the latch lever 35 is disengaged, the trigger arm 34 is free to rotate clockwise, causing the switch to move to the tripped or circuit interrupted position.

The cross link 27 is preferably a U-shaped member, as best seen in "FIG. 5. The link is assembled in one switch, the left switch of FIG. 5, with the bight of the U passing through an opening 6t in the coverplate 16. The case of the second switch is provided with a slot 61 through which the other arm of the U passes when the two switches are assembled. This design results in a completely enclosed package 'when the two switches are joined together. Of course, any number of switches could be used with a single cross link if desired. A channel-shaped boss 62 is provided in the interior of the case of each switch to serve as a pivoting guide for the cross link 27. When the circuit breaking mechanism is in the neutral position as shown in FIG. 2, the cross link 27 floats freely between the latch lever 35 and the latch release member 26. When one of the switches is tripped, the latch lever 35 is pivoted counterclockwise by the trigger arm to engage an arm of the cross link 27, as seen in FIG. 6. This engagement causes the cross link to rotate counterclockwise also and each arm of the cross link engages the corresponding latch release member 26, moving all of the latch release members downward to release all of the latch levers 35. Therefore, when any switch of the group of interconnected circuit breaker switches is tripped, all of the switches will be tripped by the coaction of the cross link, the latch release members and the latch levers.

The circuit breaking mechanism is reset from the tripped position to the neutral position by manually moving all of the finger members 33 to the extreme clockwise position. Engagement of the tip portion 46 of the finger member with the trigger arm 34 causes the trigger arm to move to the position shown in FIG. 2. Engagement of the trigger arm with the latch lever 35 causes the latch lever to move to the position of FIG. 2. A spring 64 provides a light torque urging the latch lever counterclockwise so as to be in position for engagement by the trigger arm during the reset operation. If the thermal trip member has cooled, the latch release member will be free to move upward and engage the tongue of the latch lever to latch the circuit breaking mechanism. All of the interconnected switches have to be reset at the same time and this is facilitated by means of a pin 65 passed through all of the manually operable finger members 33. Of course, the pin is not necessary to the operation of the circuit breaker switch.

The multiple circuit breaker interconnection of the present invention provides a mechanism which may be used to actuate a number of switches simultaneously. The mechanism is extremely simple and requires only one or two additional parts for incorporation into exist ing circuit breaker switches. The mechanism provides for generation of relatively large forces for switch actuation and is particularly adapted for incorporation into extremely thin circuit breaker switches without affecting the current ratings of the switches.

Although an exemplary embodiment of the invention has been disclosed and discussed, it will be understood that other applications of the invention are possible and that the embodiment disclosed may be subjected to various changes, modifications and substitutions without departing from the spirit of the invention.

I claim as my invention.

1. In a circuit breaker switch having a manually actuated ofi-on switch mechanism and an automatic circuit breaking mechanism mounted in a case, the automatic circuit breaking mechanism including a first latch member movable between a neutral position and a circuit terrupting position, a second latch member engageable with the first latch member to hold the first member in the neutral position, and a thermal trip member coupled to the second latch member for moving the second member out of engagement with the first member, the combination of: means for mounting a plurality of the witches side-by-side; and a link having a body section and parallel arms projecting therefrom, with the body ection pivotally mounted in the side-by-side switches and an arm in each switch for engagement of an arm with a latch member of a switch when such switch is in the circuit interrupted condition to move the latch members of the respective switches to the circuit interrupting position.

2. In a circuit breaker switch having a manually actuated oil-on switch mechanism and an automatic circuit breaking mechanism mounted in a case, the automatic circuit breaking mechanism including a latch movable between a neutral position and a circuit interrupted position and a trigger arm released by the latch when in the circuit interrupted position to automatically interrupt the electrical circuit, the combination of a latch release member engageable with said latch to hold said latch in a neutral position, with said latch release member biased into engagement with said latch; a thermal trip member engageable with said latch release member to move said latch release member out of engagement with said latch; means for mounting a pair of the switches side-by-side; and a U-shaped link, with the bight of the U pivotally mounted in the side-by-side switches for engagement of an arm of the U with each latch when in the circuit interrupted position to move the arms into engagement with the respective latch release members and move the latch release members out of engagement with the corresponding latches and release the trigger arm of each switch.

3. A circuit breaker switch for operation in conjunction with a similar switch, each of the switches having a manually actuated off-on switch mechanism and an automatic circuit breaking mechanism mounted in a case, the automatic circuit breaking mechanism including a latch movable between a neutral position and a circuit interrupted position and a trigger arm released by the latch when in the circuit interrupted position to automatically interrupt the electrical circuit, and including in combination: a latch release spring engageable with said latch to hold said latch in the neutral position, with said spring biased into engagement with said latch; a thermal trip member engageable with said spring to move said spring out of engagement with said latch; means for mounting the switch side-by-side with a similar switch with the switch cases having aligned openings therein; and a cross link mounted in said aligned openings for engagement by a latch when in the circuit interrupted position to move said cross link into engagement with the spring of each switch to move the spring out of engagement with the corresponding latch and release the trigger arm of each switch.

4. A plurality of circuit breaker switches mounted side-by-side, each of said switches including in combination: a case; a contact arm movably mounted in said case; an actuator for moving said contact arm from an open circuit condition to a closed circuit condition and return; a trigger arm pivotally mounted in said case, said trigger arm being movable from an on position to a trip position; means for connecting said trigger arm to said contact arm to move said contact arm to said open circuit condition when said trigger arm is in said trip position; a latch separate from and engageable with said trigger arm for maintaining said trigger arm in the on position, said latch including means for releasing said trigger arm; a latch release member for engaging said latch to maintain said trigger arm in said on position; a thermal trip member engageable with said latch release member to move said latch release member out of engagement with said latch; and a cross link movably mounted in the sideby-side switches for engagement by a latch of a switch when in the circuit interrupted position to move the cross link into engagement with the latch release member of each of the switches to move the latch release members out of engagement with the corresponding latches and release the trigger arm of each switch.

5. In a circuit breaker switch having a manually actuated oil-on switch mechanism and an automatic circuit breaking mechanism mounted in a case, the automatic circuit breaking mechanism including a latch movable between a neutral position and a circuit interrupted position and a trigger arm released by the latch when in the circuit interrupted position to automatically interrupt the electrical circuit, the combination of: a latch release member engageable with said latch to hold said latch in the neutral position; a thermal trip member engageable with said latch release member to move said latch release member out of engagement with said latch; means for mounting a plurality of the switches side-by-side; and a tie bar mounted in the side-by-side switches, said bar including an arm positioned between the latch and the latch release member of each switch for transmitting an unlatching force from a latch to all of said latch release members when such latch is moved to the circuit interrupted position.

6. In a circuit breaker switch having a manually actuated off-on switch mechanism and an automatic circuit breaking mechanism mounted in a case, the automatic circuit breaking mechanism including a latch movable between a neutral position and a circuit interrupted position and a trigger arm released by the latch when in the circuit interrupted position to automatically interrupt the electrical circuit, the combination of: a latch release spring slidably positioned in the case and engageable with said latch to hold said latch in the neutral position, with said spring biased into engagement with said latch; a thermal trip member engageable with said spring to move said spring out of engagement with said latch; means for mounting a pair of the switches side-by-side; and a U-shaped link, with the bight of the U pivotally mounted in channel-shaped supports in the side-by-side switches for engagement of an arm of the U with each latch when in the circuit interrupted position to move said link into engagement with said spring and move said spring out of engagement with the latch and release the trigger arm.

References Cited in the file of this patent UNITED STATES PATENTS 2,520,537 Speck Apr. 4, 1950 2,779,831 Thomas Jan. 29, 1957 2,875,289 Brunner Feb. 24, 1959 2,878,332 Locher Mar. 17, 1959 2,887,548 Middendorf May 19, 1959 2,934,624 Middendorf Apr. 26, 1960 2,944,128 Middendorf July 5, 1960 2,956,133 Middendorf Oct. 11, 1960 

2. IN A CIRCUIT BREAKER SWITCH HAVING A MANUALLY ACTUATED OFF-ON SWITCH MECHANISM AND AN AUTOMATIC CIRCUIT BREAKING MECHANISM MOUNTED IN A CASE, THE AUTOMATIC CIRCUIT BREAKING MECHANISM INCLUDING A LATCH MOVABLE BETWEEN A NEUTRAL POSITION AND A CURCUIT INTERRUPTED POSITION AND A TRIGGER ARM RELEASED BY THE LATCH WHEN IN THE CIRCUIT INTERRUPTED POSITION TO AUTOMATICALLY INTERRUPT THE ELECTRICAL CIRCUIT, THE COMBINATION OF: A LATCH RELEASE MEMBER ENGAGEABLE WITH SAID LATCH TO HOLD SAID LATCH IN A NEUTRAL POSITION, WITH SAID LATCH RELEASE MEMBER BIASED INTO ENGAGEMENT WITH SAID LATCH; A THERMAL TRIP MEMBER ENGAGEABLE WITH SAID LATCH RELEASE MEMBER TO MOVE SAID LATCH RELEASE MEMBER OUT OF ENGAGEMANT WITH SAID LATCH; MEANS FOR MOUNTING A PAIR OF THE SWITCHES SIDE-BY-SIDE; AND A U-SHAPED LINK, WITH THE BIGHT OF THE U PIVOTALLY MOUNTED IN THE SIDE-BY-SIDE SWITCHES FOR ENGAGEMENT OF AN ARM OF THE U WITH EACH LATCH WHEN THE CIRCUIT INTERRUPTED POSITION TO MOVE THE ARMS INTO ENGAGEMENT WITH THE RESPECTIVE LATCH RELEASE MEMERS AND MOVE THE LATCH RELEASE MEMBERS OUT OF ENGAGEMENT WITH THE CORRESPONDING LATCHES AND RELEASE THE TRIGGER ARM OF EACH SWITCH. 